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991.
992.
Feng ZHAO Yuchen CHEN Bin QIAO Jing WANG Ping NA 《Frontiers of Chemical Science and Engineering》2012,6(3):292
Inorganic arsenicals, including arsenite (AsIII) and arsenate (AsV), are well-known human carcinogens. Recently, studies have indicated that arsenic triglutathione (As(GS)3) is unstable in an aqueous solution. The present study was designed to evaluate the degradation mechanism of As(GS)3 in an aqueous solution using high-performance liquid chromatography-electrospray ionisation mass spectrometry (HPLC-ESI-MS). Based on the fragments obtained from MS2 and MS3, we identified two new compounds: one was an isomer of glutathione (GSH), and the other was a product from the cleavage of the glutamyl of oxidised glutathione (GSSG). The isomerization of GSH resulted in the loss of its function such as detoxification of many reactive metabolites. The formation of the two new compounds affected the ratio of GSH/GSSG, and thus may affect the antioxidant and detoxification of GSH/GSSG in mammalian cells. 相似文献
993.
A liquid metal magnetohydrodynamics generation system (LMMGS) was proposed and demonstrated in this paper for collecting parasitic power in shoe while walking. Unlike the conventional shoe-mounted human power harvesters that use solid coil and gear mechanism, the proposed system employs liquid metal (Ga62In25Sn13) as energy carrier, where no moving part is requested in magnetohydrodynamics generators (MHGs). While walking with the LMMGS, the foot alternately presses the two liquid metal pumps (LMPs) which are respectively placed in the front and rear of the sole. As a result, the liquid metal in the LMPs (LMP I and II) is extruded and flows through the MHGs (MHG I and II) in which electricity is produced. For a comparison, three types of LMMGSs (LMMGS A, B and C) were built where all the parts are the same except for the LMPs. Furthermore, performances of these LMMGSs with different volume of injected liquid metal were tested respectively. Experimental results reveal that both the output voltage and power of the LMMGS increase with the volume of injected liquid metal and the size of the LMPs. In addition, a maximum output power of 80 mW is obtained by the LMMGS C with an efficiency of approximately 1.3%. Given its advantages of no side effect, light weight, small size and reliability, The LMMGS is well-suited for powering the wearable and implantable micro/nano device, such as wearable sensors, drug pumps and so on. 相似文献
994.
995.
At present, the research on circular economy has made a lot of substantive results both at home and abroad. But for the papermaking enterprise, which is the representative of the light industry, few studies have analyzed the evaluation index system of circular economy. Since the current material flow analyses have limitations that the researchers cannot calculate materials with different units. The authors take advantage of the intrinsic correlation between the basic principle of value flow analysis and circular economy, and then analyze the dynamic changes of material flow and value flow through enterprises internal production process. Considering the resource output, the authors set up the layered structure of the evaluation index system, and then preliminarily determine the index form. Next, the authors use the frequency statistics analysis method to adjust indicators, forming a preliminary index system. After that, the principal component analysis and independent analysis are applied for screening. Finally, the authors build a circular economy evaluation index system for papermaking enterprise to provide scientific guidance for the process of circular economy. 相似文献
996.
Flash solid-state drives (SSDs) provide much faster access to data compared with traditional hard disk drives (HDDs). The current price and performance of SSD suggest it can be adopted as a data buffer between main memory and HDD, and buffer management policy in such hybrid systems has attracted more and more interest from research community recently. In this paper, we propose a novel approach to manage the buffer in flash-based hybrid storage systems, named hotness aware hit (HAT). HAT exploits a page reference queue to record the access history as well as the status of accessed pages, i.e., hot, warm, and cold. Additionally, the page reference queue is further split into hot and warm regions which correspond to the memory and flash in general. The HAT approach updates the page status and deals with the page migration in the memory hierarchy according to the current page status and hit position in the page reference queue. Compared with the existing hybrid storage approaches, the proposed HAT can manage the memory and flash cache layers more effectively. Our empirical evaluation on benchmark traces demonstrates the superiority of the proposed strategy against the state-of-the-art competitors. 相似文献
997.
Bin LIN Shanshan LI Xiangke LIAO Jing ZHANG Xiaodong LIU 《Frontiers of Computer Science》2014,8(2):175-183
Deduplication technology has been increasingly used to reduce storage costs. Though it has been successfully applied to backup and archival systems, existing techniques can hardly be deployed in primary storage systems due to the associated latency cost of detecting duplicated data, where every unit has to be checked against a substantially large fingerprint index before it is written. In this paper we introduce Leach, for inline primary storage, a self-learning in-memory fingerprints cache to reduce the writing cost in deduplication system. Leach is motivated by the characteristics of real-world I/O workloads: highly data skew exist in the access patterns of duplicated data. Leach adopts a splay tree to organize the on-disk fingerprint index, automatically learns the access patterns and maintains hot working sets in cachememory, with a goal to service a majority of duplicated data detection. Leveraging the working set property, Leach provides optimization to reduce the cost of splay operations on the fingerprint index and cache updates. In comprehensive experiments on several real-world datasets, Leach outperforms conventional LRU (least recently used) cache policy by reducing the number of cache misses, and significantly improves write performance without great impact to cache hits. 相似文献
998.
超细粉体凹凸棒石助凝去除富营养化河水中的藻类 总被引:1,自引:0,他引:1
考察了投加超细粉体(200目)凹凸棒石对聚合氯化铝(PAC)混凝沉淀去除富营养化河水中藻类的影响.结果表明,添加凹凸棒石能大大提高PAC对浊度和叶绿素a的去除效果.且可以明显增加絮体的密度,改善絮体的沉降性能,抑制絮体中藻类的上浮.当PAC投量为40ms/L、凹凸棒石投量为0.08%时,PAC与凹凸棒石联用对浊度和叶绿素a的去除率较单用PAC时分别提高了14.5%和14.0%,形成的絮体沉降体积仅为单用PAC时的1/2,降低了后续处理难度. 相似文献
999.
1000.
以炼铜炉渣选铜尾矿资源化利用为目的,选用某有色金属公司炼铜炉渣的选铜尾矿为原料,采用条件实验、正交实验等研究方法和化学分析、原子吸收、XRD、SEM等检测手段,通过多因素优化实验考察砂浆的流动度,试块不同龄期的抗压强度以此确定微粉的活性指标,研究炼铜炉渣选铜尾矿制备矿微粉的可行性。结果表明:铜渣再选尾矿微粉的比表面积、激发剂、助磨剂和减水剂对制备矿微粉均具有一定的影响,其影响次序为:矿微粉的比表面积>激发剂(Na2SO4)>减水剂>助磨剂(三乙醇胺)。当铜渣再选尾矿微粉掺量为10%时,可满足活性指数大于95%(S95级别)的标准要求,此时7天和28天的活性指数分别为97.56%和95.91%;而在尾矿微粉掺量为20%~30%时,可满足活性指数大于75%(S75级别)的标准要求。相关助剂的添加提高了铜渣再选尾矿的粉磨效率,细小颗粒有益于碱激发过程的发生,使得砂浆更加致密。重金属浸出表明,Cr、Cd的浸出量与水泥相比增加较小,Cu有少量增加,对环境影响较小,为工业固废资源化协同利用提供了新的发展途径。 相似文献